RU1827651C - Apparatus for electrodynamic testing of power transformer - Google Patents

Abstract

Usage: relates to electrical testing equipment and can be used in electrodynamic tests of power transformers in short circuit mode. The inventive device for electrodynamic testing of power transformers (T) contains 1 three-phase (TF) power source (1), 1 TF protective switch (2), TF test T (3), 1 short circuit (4), TF test T (5 ), connected in series with each other, parallel to the primary winding, to two inexpressible phases 7 and 8 of test T5, 1 inductive resistance (reactor) is switched on (12), and this reactor (12) has the same quality factor as the shorted test T (5). The device allows testing high-power high-voltage transformers with a low class of neutral output voltage of the primary winding according to a single-phase test scheme using two other phases. 2 ill.

Description

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The invention relates to electrical testing equipment and can be used in electrodynamic testing of power transformers in short circuit mode.

The aim of the invention is to expand the scope of application by making it possible to carry out tests at high shock currents of power transformers.

The drawing shows a diagram of the proposed device.

The device comprises a voltage source 1, a protective switch 2, a three-phase test transformer 3, a three-phase test transformer 5 with primary and secondary windings 6, 7,

8 and 9, 10, 11, respectively, short circuit 4, additional shunt inductive reactor 12. Moreover, the neutral terminals of the primary and secondary windings of the test transformer Ј are grounded, the first terminal of the short circuit 4 is connected to the terminal of one of the phases of the secondary winding of the test transformer 3, others the conclusions of which are interconnected, the conclusions of the corresponding phases of the primary winding of the test transformer 3 are connected to the first output terminal of the protective switch 2, the second output terminal of which is connected n with the third phase terminal of the primary winding of the test transformer 3, the input terminals of the protective switch 2

connected to the corresponding phases of voltage source 1, the terminals of the secondary winding 9, 10, 11 of the test transformer 5 are connected to each other, the second terminal of the short circuit 4 is connected to the terminal of the first phase of the primary winding 6 of the test transformer 5, the second and third of phase 7, 8 of which are connected in parallel each other and have a common neutral with the first phase. An additional shunt inductive reactor 12 is connected in parallel with the second and third phases 7, 8 of the primary winding of the transformer under test 5.

The complex resistance of the additional shunt inductive reactor 12 is determined from the expression

Ks (3 + 1.5 a) / (3+ a),

where a is the ratio of the complex resistance of the additional inductive reactor 12 to the total resistance of one phase of the transformer under test 5;

Ks is the coefficient of increase in test power required to conduct electrodynamic tests of a given transformer compared to the prototype device.

 according to the formula, we get the values, 12, i.e. approximately 12% less power is required for the excitation source, or, conversely, for a given power supply, it is possible to test a transformer with a power 12% greater than when using the prototype device.

Claims (1)

The claims Device for electrodynamic testing of power transformers, co0 5 0 5 0 5 0 holding voltage source, protective switch, test transformer having grounded neutrals of the primary and secondary windings, a short circuit, the first output of which is connected to the output of one of the phases of the secondary winding of the test transformer, the other leads of which are interconnected, the conclusions of the corresponding phases of the primary winding of the tested transformer connected to the first terminal of the protective switch, the second terminal of which is connected to the third phase terminal of the primary winding of the transformer under test, input the terminals of the protective switch are connected to the corresponding phases of the voltage source, the terminals of the secondary winding of the transformer under test are interconnected, the second terminal of the short circuit is connected to the terminal of the first phase of the primary winding of the transformer under test, the second and third phases of which are connected in parallel and have a common neutral with the first phase, characterized in that, in order to expand the scope of application, an inductive reactor is introduced into it, connected in parallel with the second and third phases of the primary winding th transformer, and its complex impedance is determined from the expression Ks (3 + 1.5 a) / (3 + a), where a is the ratio of the complex resistance of the inductive reactor to the total resistance of one phase of the transformer under test; Ks is the coefficient of increase in test power.